Title :
Partial discharge signal propagation characteristics inside the winding of oil-immersed power transformer - using the three-winding transformer model in air
Author :
Okabe, Shigemitsu ; Ueta, Genyo ; Wada, Haruhisa
Author_Institution :
Tokyo Electr. Power Co., Yokohama, Japan
fDate :
12/1/2011 12:00:00 AM
Abstract :
The soundness of a power transformer under an operating voltage is evaluated in partial discharge (PD) test of long-duration ac withstand voltage test. To establish clear control criteria for this PD test, it is necessary to study PD propagation characteristics inside the transformer windings. In this paper, a study was conducted on PD signal propagation characteristics for an oil-immersed transformer. This involved a winding model of a three- winding transformer, or the structure of an actual transformer being produced to investigate the PD signal propagation characteristics relative to the occurrence position, measurement position, and front time of the PD as parameters. Subsequently, since a preceding study on a gas-filled transformer confirmed that an equivalent circuit of the winding could be used for analytical evaluation, an analysis model was also constructed for a three-winding model of the oil-immersed transformer in the present study to investigate the propagation characteristics. Consequently, it emerged that an analysis using an equivalent circuit could also effectively simulate the propagation characteristics, waveform shape, and transmission rate for an oil- immersed transformer. As for the transmission rate, it was found that the signal was detected as significantly damped to a level of several percent depending on the occurrence and measurement positions of the PD, as was also the case for a gas-filled transformer.
Keywords :
equivalent circuits; partial discharges; power transformer insulation; power transformer testing; transformer oil; transformer windings; PD test; equivalent circuit; gas-filled transformer; long-duration AC withstand voltage test; measurement position; occurrence position; oil-immersed power transformer winding; partial discharge signal propagation characteristics; three-winding transformer model; transmission rate; Integrated circuit modeling; Oil insulation; Partial discharges; Power transformer insulation; Voltage measurement; Windings; ERA; Electro MagneticTransients Program (EMTP); Oil-immersed power transformer; controlvalue; partial discharge (PD); propagation characteristics; transmission rate;
Journal_Title :
Dielectrics and Electrical Insulation, IEEE Transactions on
DOI :
10.1109/TDEI.2011.6118640